In south Brevard County, there is Harris Corp. And then there is Harris Corp.

The $2 billion electronics-manufacturing company, whose product line spans the computer and communications industries, is the dominant private employer in all of Brevard County and the biggest industrial employer in all of Florida. But it is in the southern end of the county -- in the cities of Melbourne, Palm Bay and Malabar -- where its presence and influence are greatest.

That isn't likely to change anytime soon. Harris chairman and chief executive Joseph A. Boyd said recently the company has no plans to move its corporate headquarters from Melbourne, although he acknowledged the company is a potential takeover target. Of the 30,000 Harris employees worldwide, about 12,000 are in Florida, principally in Brevard County and in Fort Lauderdale. A contingent of about 400 work in east Orange County on research and development connected to military avionics testing equipment.

Harris workers are involved in the research, design and manufacture of a host of products ranging from satellite earth stations to superminicomputers. Harris is a leading supplier of telecommunications and computer equipment and ranks among the top 10 domestic makers of semiconductors. Its customers include members of the Fortune 1,000 and the departments of defense of various countries.

That diversity -- being a supplier to both business and government -- has helped Harris weather many storms. It is the prime reason why stock analysts remain bullish on the company despite the severe slumps in both the semiconductor and computer companies.

''Their diversification does provide them some relative strength on the downside,'' said Geoffrey M. Hance, director of research at Blackstock & Co. in Jacksonville. ''They're in a lot of the right markets.''

The Harris fiscal year ended June 30, and while the company hasn't released its year-end results, Boyd said the fourth quarter will reflect the depressed state of affairs in both the company's semiconductor and information systems divisions. Those two accounted for more than 20 percent of the company profit last year.

In the third quarter ended March 29, Harris earned $17.2 million on revenue of $574.1 million, compared with $19.8 million on revenue of $502.5 million for the same period a year earlier. Commenting at the time of the third-quarter earnings release, Boyd said Harris would experience a decline in profitability in the fourth quarter but overall 1985 profits would be slightly higher than the $80.4 million recorded in 1984.

''The semiconductor situation has continued to deteriorate,'' Boyd said in an interview in mid-July. Sales of custom semiconductors and those made for the military, such as radiation-hardened chips, have been good but there is a weakness in orders for semiconductors that use complementary metal oxide semiconductor (CMOS) technology. Overall, the company's semiconductor division lost money in the third quarter.

Harris was a leader in the development of CMOS but is facing stiff competition from the Japanese. Another new technology to which Harris is committing itself is the use of gallium arsenide in place of the more common silicon in the manufacture of integrated circuits. But gallium arsenide is still ''developmental only'' and loses money for the company, Boyd said.

Another weak spot is the company's Information Systems division, which is being battered by stiff competition and sluggish demand for such items as IBM- compatible data terminals and private branch telephone exchanges. Last year, Harris said it was merging its Lanier Business Products sector into Information Systems, thereby creating the company's largest division, with $800 million in annual sales.

Although analysts questioned the 1983 merger of low-end Lanier with high- end Harris, Boyd has apparently proved the skeptics wrong. At a time of widespread hardship in the office automation equipment industry, Lanier has posted a strong performance and is a bright star in the Harris firmanent, Boyd said.

''The fact is, they've done great,'' he said.

Looking to the future, Boyd forecast continued growth for the company, both in terms of sales and employment. The company ranks fifth among Florida's defense contractors and military business accounts for about a third of all Harris sales. Once the current cyclical downturn in the semiconductor industry abates, Harris should be well-positioned to capitalize on the rebound.

Perhaps a bigger cloud is the threat of a hostile takeover. Last year, there were rumblings of a Kodak bid for Harris but nothing came of the rumors. Still, Boyd concedes that Harris stock is trading close to its book value -- it closed Friday at 28 1/2 -- and that makes the company attractive to outsiders.

''You have to worry about something like that,'' Boyd said, adding, ''We'd like to think we're going to be one of the survivors.''